Dresden 2000 – wissenschaftliches Programm

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HK: Physik der Hadronen und Kerne

HK 13: Postersitzung / Instrumentation und Anwendungen

HK 13.25: Poster

Donnerstag, 23. März 2000, 10:15–12:45, B 117

Improvements of the FLUKA simulation code for radiobiological applications — •Katia Parodi¹ and Sandro Squarcia² — ¹Forschungszentrum Rossendorf e.V., Postfach 51 01 19, D-01314 Dresden — ²Dipartimento di Fisica, Via Dodecaneso 33, I-16146 Genova

Monte Carlo methods are actually the best tools to perform the detailed dosimetric and radiobiological calculations required in conformal radiotherapy. On the basis of the choice of the FLUKA simulation code as a suitable instrument for medical tasks, the electronic stopping power calculations for protons and α particles in materials of clinical interest were tested. The electronic stopping power is in fact the main physical quantity related to the therapeutic effectiveness of charged hadrons. Furthermore ¹H and ⁴He nuclei are important in hadrontherapy both as primaries and secondaries produced in nuclear reactions, especially induced by primary neutrons. The examination showed evidencence of stopping power calculations deviating from values suggested by ICRU (standard reference in matter of medical applications of radiations) up to 20% for protons in compounds and up to 50% for α particles both in elements and compounds in the energy region below 1 A MeV. Since these inaccuracies could affect radiobiological investigations, the old standard Monte Carlo approach (based on the additivity Bragg’s rule and scaling) was abandoned and a new parametrization of ICRU data was developed. The new algorithms work on the entire energy range 1 keV-100 A MeV spanned by the old ones, allowing an agreement with ICRU data within 1% below 1 A MeV and less than 1% in the upper region for protons in compounds and for α particles both in elements and compounds.